Power supply question 240volt 3phase power vs 1 phase

[philipma1957]

okay I have a glut of power supplies

 Evga  1300 g2
 Evga  1300 g2
 Evga  1600 p2

Seasonic 1200 plat
Seasonic   750 plat
Seasonic   650 gold
Seasonic   650 gold

Antec       600 plat

Intel server   1000 watt 120vol  1200 watt 240 volt plat

I finally wired one socket to 240 volts in house and I have a good improvement.


but all of the above is back ground info.  I have a friend that can give me 30 amps of 240 volt power at 7 cents a kwatt  but it is 3 phase so pardon some lack of knowledge on my part can an atx psu run on 3 phase power source.  I know the power wave on 3 phase is staggered but at that point I run out of knowledge. 

Short of plugging in an atx psu to test for shorting overloading or shaky 12 volt pc output, what is the story on 3phase vs 1 phase for atx psu's.

I think all of my psu's have active  PFC if that is helpful.

[1714805536]

1714805536

[1714805536]

1714805536

[1714805536]

1714805536

[LordPaco]

This confused me too at first before I did some research into three phase. I like to think of it like this (and please pardon my newb explanations):

Single phase AC has two hots, with each hot maximum potential 180degrees out of phase each cycle(hertz)

Three phase AC has three hots, with each hot maximum potential 120 degrees out of phase each cycle. Think of this like a triangle instead of a teeter totter.

You can use Three phase as single phase, just use two hots from the three phase. Of course this will only put a load on one 'side' of the three-phase triangle. The additional trick needed for three phase is 'balancing' the load of all three 'sides/phases' of that triangle so power is pulled evenly. Ammeters on each phase can provide a visual representation of what is going on, or you can just depend on careful calculation and wiring. Transformer life and many other thinks can quickly deteriorate if you are running unbalanced in any significant way.

So with just one more hot with 3 phase, you essentially can pull single phase from three points.

An example with a 3 phase pdu I have: 3 phase power cord, 60A, @ 208V. It has 6 C-19 outlets on it. Outlets 1-2 are connected to Phases A-B. Outlets 3-4 are connected to phases B-C. Outlets 5-6 are connected to phases C-A. It will not self balance, but requires that similar loads are put on these groups of outlets.

Here is a number you should memorize (it is not exact but gets you close enough)

1.732

To calculate wattage available from 3 phase : AMPS X 1.732 X VOLTAGE

Hope some of this helps, three phase is cool beans!

[philipma1957]

This confused me too at first before I did some research into three phase. I like to think of it like this (and please pardon my newb explanations):

Single phase AC has two hots, with each hot maximum potential 180degrees out of phase each cycle(hertz)

Three phase AC has three hots, with each hot maximum potential 120 degrees out of phase each cycle. Think of this like a triangle instead of a teeter totter.

You can use Three phase as single phase, just use two hots from the three phase. Of course this will only put a load on one 'side' of the three-phase triangle. The additional trick needed for three phase is 'balancing' the load of all three 'sides/phases' of that triangle so power is pulled evenly. Ammeters on each phase can provide a visual representation of what is going on, or you can just depend on careful calculation and wiring. Transformer life and many other thinks can quickly deteriorate if you are running unbalanced in any significant way.

So with just one more hot with 3 phase, you essentially can pull single phase from three points.

An example with a 3 phase pdu I have: 3 phase power outlet, 60A, @ 208V. It has 6 C-19 outlets on it. Outlets 1-2 are connected to Phases A-B. Outlets 3-4 are connected to phases B-C. Outlets 5-6 are connected to phases C-A. It will not self balance, but requires that similar loads are put on these groups of outlets.

Here is a number you should memorize (it is not exact but gets you close enough)

1.732

To calculate wattage available from 3 phase : AMPS X 1.732 X VOLTAGE

Hope some of this helps, three phase is cool beans!

okay the guy's shop has a ton of 3 hole twist-lock receptacles . I think I need to measure the power on them as

I thought they looked like this





these would have 2 hots and a ground  each hot would be a 120 if you went hot to ground.  but if you go hot to hot you get 240.

if  measure his power and get that result  it would be more like 1 phase.

your description has me a bit confused maybe his  shop wiring is doing what you say if I understand you correctly  3 hots feed into his shop.

and each 3 prong twist plug he has is using 2 of the 3 hots.

So if I want to load balance. with the 3 hots named 1 2 3

    I make 3  receptacles

  1+2+g is the first plug
  2+3+g is the second plug
  1+3+g is the third plug

each one does a evga 1300g2 running at 1000 watts   and we are load balanced

[LordPaco]

That is a NEMA L6-30. for Single phase 240v applications, the three conductors you see there are for hot-hot-ground. Three phase will have either 4 or 5 conductors. They would be hot-hot-hot-ground, or alternatively hot-hot-hot-neutral-ground.

https://en.wikipedia.org/wiki/NEMA_connector#NEMA_6

[LordPaco]

You could engineer/wire it in a way that it pulls from two of the phases straight from the panel so you could use such an outlet on a three phase panel. That may be what he is doing and probably the norm. I'm setting up my datacenter with 3 phase PDU's so I bring all 3 phases out from the panels to closer to where it's used. More efficient that way, less metal to conduct more power.

[philipma1957]

You could engineer/wire it in a way that it pulls from two of the phases straight from the panel so you could use such an outlet on a three phase panel. That may be what he is doing and probably the norm. I'm setting up my datacenter with 3 phase PDU's so I bring all 3 phases out from the panels to closer to where it's used. More efficient that way, less metal to conduct more power.

okay I think I get it.

Next question  what are each of you hot wires carrying 120 volts?   1.732 X 120 = 208

[LordPaco]

I will only be using 208V exclusively for miners, so none of the hots carry 120V. There are 5-wire 3 phase pdu setups that also bring in the neutral to allow you to go from phase to neutral to achieve that. I haven't been able to find any of those guys in the high wattage dept at the scrapyards.

[philipma1957]

I will only be using 208V exclusively for miners, so none of the hots carry 120V. There are 5-wire 3 phase pdu setups that also bring in the neutral to allow you to go from phase to neutral to achieve that. I haven't been able to find any of those guys in the high wattage dept at the scrapyards.

I GOT A HOLD  of 3 very nice pdu's

Each is 24 amps 3 wire hot-hot-ground twist lock.

 Price was under 80 for the 3 combined .

so if I make the 3 receptacles correctly I should have 3 balanced pdu's my guess is all the hots are going to be 120.

I am going to have an excess of power for a change.

[LordPaco]

If your going from hot <-> hot it will be 208/240v. But thats not a bad thing, unless you absoletely have to have 120/110 skip it. I'll bet all your bronze rated ATX PSUS's or better not older than 2 years will automatically switch and run better with the higher voltage.

Here is a picture of a box my brother in law made up for me, we will hang one of these above each 400A 208V 3-phase panel to have a visual proof of what is being used and how balanced. FYI these meters were $5.08 each off alibaba  (they also require a CT)

[klondike_bar]

these would have 2 hots and a ground  each hot would be a 120 if you went hot to ground.  but if you go hot to hot you get 240.
if  measure his power and get that result  it would be more like 1 phase.
your description has me a bit confused maybe his  shop wiring is doing what you say if I understand you correctly  3 hots feed into his shop.
and each 3 prong twist plug he has is using 2 of the 3 hots.
So if I want to load balance. with the 3 hots named 1 2 3

    I make 3  receptacles

  1+2+g is the first plug
  2+3+g is the second plug
  1+3+g is the third plug

each one does a evga 1300g2 running at 1000 watts   and we are load balanced

^that sounds correct. Thats a 30A receptacle, meaning you can load 5.5-6kW on it (208 and 240V respectively, achieving 80% load). It would connect to your breaker panel using a 2-pole breaker (plus GND)

Now if you have a 30A 3-phase, thats a bit different and is quite unlikely to be seen in a residential building. (90% of homes are 2-phase, each at 120V, to allow 240V when running both phases). A 3-phase breaker will only work properly on a 3-phase panel - on a 2-phase panel you would have 2 rows of 240V sockets, and one row of 0V (since its 2 hot lines of the same busbar)

3-phase is generally for industrial, where power is stepped down from a 600V service, giving 3 hot lines, each at 120V or with a difference of 208V between any two lines. You should balance the load across the three phases

[philipma1957]

these would have 2 hots and a ground  each hot would be a 120 if you went hot to ground.  but if you go hot to hot you get 240.
if  measure his power and get that result  it would be more like 1 phase.
your description has me a bit confused maybe his  shop wiring is doing what you say if I understand you correctly  3 hots feed into his shop.
and each 3 prong twist plug he has is using 2 of the 3 hots.
So if I want to load balance. with the 3 hots named 1 2 3

    I make 3  receptacles

  1+2+g is the first plug
  2+3+g is the second plug
  1+3+g is the third plug

each one does a evga 1300g2 running at 1000 watts   and we are load balanced

^that sounds correct. Thats a 30A receptacle, meaning you can load 5.5-6kW on it (208 and 240V respectively, achieving 80% load). It would connect to your breaker panel using a 2-pole breaker (plus GND)

Now if you have a 30A 3-phase, thats a bit different and is quite unlikely to be seen in a residential building. (90% of homes are 2-phase, each at 120V, to allow 240V when running both phases). A 3-phase breaker will only work properly on a 3-phase panel - on a 2-phase panel you would have 2 rows of 240V sockets, and one row of 0V (since its 2 hot lines of the same busbar)

3-phase is generally for industrial, where power is stepped down from a 600V service, giving 3 hot lines, each at 120V or with a difference of 208V between any two lines. You should balance the load across the three phases

I got 2 phase in house and finally did 2 circuits into 240volts.

My friend  with cheaper power has ' 240 volts 3 phase'  and runs a lot of heavy machinery in his shop..   those quotes are what he told me.

When I go back to his  place I will bring a meter and figure out what he really has.

In my home the one I wired with 30amp 2 pole breaker to a 30 amp plug is 10 gauge a 35 foot run.  What can 10 gauge handle safely?

  The pdu is fused for 24amps.

   I know 12gauge is okay for a 20amp 2 pole 240 volt.

Is 10 gauge okay for a 30 amp 2 pole 240 volt.  1 single 240 l6-30r plug to a 24amp pdu.  TIA

[Prelude]

Yes, 10 AWG is what is needed for 30A, you're fine at 35'. Your PDU is likely also 30A, but derated (80%) to 24A. I've run my PDUs at 30A without issue, but try to keep them at a max of 27A.

How are you liking the switch to 240v from 120v? 

[DaBitcoinGuy]

http://www.altatech.com.br/media/catalog/product/cache/1/image/5e06319eda06f020e43594a9c230972d/a/p/apc-770-0013.jpg
these would have 2 hots and a ground  each hot would be a 120 if you went hot to ground.  but if you go hot to hot you get 240.
if  measure his power and get that result  it would be more like 1 phase.
your description has me a bit confused maybe his  shop wiring is doing what you say if I understand you correctly  3 hots feed into his shop.
and each 3 prong twist plug he has is using 2 of the 3 hots.
So if I want to load balance. with the 3 hots named 1 2 3

    I make 3  receptacles

  1+2+g is the first plug
  2+3+g is the second plug
  1+3+g is the third plug

each one does a evga 1300g2 running at 1000 watts   and we are load balanced

^that sounds correct. Thats a 30A receptacle, meaning you can load 5.5-6kW on it (208 and 240V respectively, achieving 80% load). It would connect to your breaker panel using a 2-pole breaker (plus GND)

Now if you have a 30A 3-phase, thats a bit different and is quite unlikely to be seen in a residential building. (90% of homes are 2-phase, each at 120V, to allow 240V when running both phases). A 3-phase breaker will only work properly on a 3-phase panel - on a 2-phase panel you would have 2 rows of 240V sockets, and one row of 0V (since its 2 hot lines of the same busbar)

3-phase is generally for industrial, where power is stepped down from a 600V service, giving 3 hot lines, each at 120V or with a difference of 208V between any two lines. You should balance the load across the three phases

I got 2 phase in house and finally did 2 circuits into 240volts.

My friend  with cheaper power has ' 240 volts 3 phase'  and runs a lot of heavy machinery in his shop..   those quotes are what he told me.

When I go back to his  place I will bring a meter and figure out what he really has.

In my home the one I wired with 30amp 2 pole breaker to a 30 amp plug is 10 gauge a 35 foot run.  What can 10 gauge handle safely?

  The pdu is fused for 24amps.

   I know 12gauge is okay for a 20amp 2 pole 240 volt.

Is 10 gauge okay for a 30 amp 2 pole 240 volt.  1 single 240 l6-30r plug to a 24amp pdu.  TIA

10 gauge copper is good for 30 amps, 10 gauge aluminum is 25 amps.

[adaseb]

3 phase is generally used for generators. You can use it to mine by looking at the similar diagram.

[MCHouston]

The PSU will not see a difference as far as the number of phases go, cause it will only see two phases regardless of single or three phase grid feeds.  You are probably better to go with three phase 240V or single phase 240V since its higher voltage.  Depending on Wye, Delta or high leg your voltage from two of the legs of a three phase circuit can be 208V or 240V.

[Meech]

From what I gathered from a electrician is 3 phase is used in industrial areas and devices have to be split evenly across all three phases.  It can run more efficiently if used properly but for our uses and for the future single phase is best for you.

[philipma1957]

Yes, 10 AWG is what is needed for 30A, you're fine at 35'. Your PDU is likely also 30A, but derated (80%) to 24A. I've run my PDUs at 30A without issue, but try to keep them at a max of 27A.

How are you liking the switch to 240v from 120v?  

gear seems to do higher hash rates and less power draw.

Not a lot maybe 2 percent and 2 percent  but that is around a 4 percent improvement.

 My cost to do it was under 150 usd for 2 circuits and  that is  counting 3 good pdus on ebay.

http://www.ebay.com/itm/121380956007?

http://www.ebay.com/itm/121298867226? >>>>>>>>>> he still has some of these.

[Finksy]

Yes, 10 AWG is what is needed for 30A, you're fine at 35'. Your PDU is likely also 30A, but derated (80%) to 24A. I've run my PDUs at 30A without issue, but try to keep them at a max of 27A.

How are you liking the switch to 240v from 120v?  

gear seems to do higher hash rates and less power draw.

Not a lot maybe 2 percent and 2 percent  but that is around a 4 percent improvement.

 My cost to do it was under 150 usd for 2 circuits and  that is  counting 3 good pdus on ebay.

http://www.ebay.com/itm/121380956007?

http://www.ebay.com/itm/121298867226? >>>>>>>>>> he still has some of these.

The gain in PSU efficiency is understandable, but do you really think the higher hashrate was due to the AC input voltage to the Power supply?  Have you checked the DC voltage?

I honestly know nothing about 3-phase, but I would be cautious as to how you split the legs up to convert it to single phase...
Here is an article about using transformers to convert between three phase and single phase: http://carroll-meynell.com/technical-3phase

[philipma1957]

short term I will be doing 240 volt in house. long term I have to see exactly how his shop is wired.

I would love to have a 30 amp circuit .

His shop is 1 large room around 1200 square feet . It has 16 foot ceilings. 7 cent power. Would be nice to run a lot of gear .

5 evga 1300's could do a lot. Even 4 would be nice.

[charles2k]

I am in Europe. At home I have 3x25A 230V splitted to several parts:

one phase
- 3x 16A - for wall sockets (each max. 3680W)
- 2x 10A - for lights
3 phases
- one separate for 5,5kW electric stove

Usually I have simultaneously aprox. 9kW (miners in wall sockets) and also no problem when I work with 5,5kW electric stove.